A fuel cell has been proposed as a clean, efficient and environmentally responsible power source for electric vehicles and various other applications. Individual fuel cells can be stacked together in series to form a fuel cell stack for various applications. The fuel cell stack is capable of supplying a quantity of electricity sufficient to power a vehicle. In particular, the fuel cell stack has been identified as a potential alternative for the traditional internal-combustion engine used in modern automobiles.
One type of fuel cell is the polymer electrolyte membrane (PEM) fuel cell. The PEM fuel cell includes three basic components: an electrolyte membrane; and a pair of electrodes, including a cathode and an anode. The electrolyte membrane is sandwiched between the electrodes to form a membrane-electrode-assembly (MEA). The MEA is typically disposed between porous diffusion media (DM) such as carbon fiber paper, which facilitates a delivery of reactants such as hydrogen to the anode and oxygen to the cathode. In the electrochemical fuel cell reaction, the hydrogen is catalytically oxidized in the anode to generate free protons and electrons. The protons pass through the electrolyte to the cathode. The electrons from the anode cannot pass through the electrolyte membrane, and are instead directed as an electric current to the cathode through an electrical load such as an electric motor. The protons react with the oxygen and the electrons in the cathode to generate water.
It has been desirable to fabricate the fuel cell and related fuel cell components from radiation-sensitive materials. The formation of structures such as micro-truss structures from radiation-sensitive materials are described in Assignee's co-pending U.S. patent application Ser. No. 12/339,308, the entire disclosure of which is hereby incorporated herein by reference. The formation of radiation-cured fuel cell components is further described in Assignee's co-pending U.S. patent application Ser. Nos. 12/341,062, 12/341,105, 12/603,147, 12/466,646, 12/466,405, and 121603,120, the entire disclosures of which are hereby incorporated herein by reference.
Known fuel cells formed from radiation-sensitive materials have had a conductive plating on diffusion media features that was relatively thinner than a conductive plating on flow field features. Other fabrication processes have also generally been performed between the respective plating processes in order to form additional features of the radiation-cured fuel cell. These additional processing steps are undesirable and add to manufacturing complexity.
There is a continuing need for a fuel cell component fabricated from radiation-sensitive materials which integrates both diffusion media and a bipolar plate into a single component, and a method for fabricating the fuel cell component with a minimum number of process steps. Desirably, the fuel cell component and method facilitates a continuous process sequence, permits a removal of all uncured radiation-sensitive material in a single step, and allows for a single plating process for both the diffusion media and the flowfields of the fuel cell component.